Direction Interrégionale de LA REUNION
B.P.4    97491 Ste Clotilde Cedex
Téléphone                02.62.92.11.00
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RSMC / TROPICAL CYCLONE CENTRE / LA REUNION TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN) 0.A WARNING NUMBER : 7/2/20082009 1.A TROPICAL DISTURBANCE 2 2.A POSITION 2008/10/18 AT 0000 UTC : WITHIN 30 NM RADIUS OF POINT 8.1S / 68.8E (EIGHT DECIMAL ONE DEGREES SOUTH AND SIXTY EIGHT DECIMAL EIGHT DEGREES EAST) 3.A DVORAK ANALYSIS : 2.0/2.0 /S 0.0/24 H 4.A CENTRAL PRESSURE : 1001 HPA 5.A MAX AVERAGE WIND SPEED (10 MN) : 25 KT 6.A EXTENSION OF WINDS BY QUADRANTS (KM): 7.A FIRST CLOSED ISOBARE (PRESSURE / AVERAGE DIAM): 1005 HPA / 1000 KM 8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION: DEEP 1.B FORECASTS: 12H: 2008/10/18 12 UTC: 09.6S/68.2E, MAX WIND=030KT, TROP. DEPRESSION. 24H: 2008/10/19 00 UTC: 10.8S/66.8E, MAX WIND=030KT, TROP. DEPRESSION. 36H: 2008/10/19 12 UTC: 11.7S/65.2E, MAX WIND=030KT, TROP. DEPRESSION. 48H: 2008/10/20 00 UTC: 12.7S/63.6E, MAX WIND=030KT, TROP. DEPRESSION. 60H: 2008/10/20 12 UTC: 13.3S/62.3E, MAX WIND=035KT, MODERATE TROP. STORM. 72H: 2008/10/21 00 UTC: 13.3S/60.9E, MAX WIND=040KT, MODERATE TROP. STORM. 2.B OTHER INFORMATIONS: T=CI=2.0 1636Z ASCAT SWATH CONFIMRS THAT WINDS NEAR THE CENTER DIDN'T REACH NEAR GALE FORCE WINDS 30KT ANYMORE. 30/35 KT EXISTS HOWEVER FAR FROM THE CENTER BETWEEN 240KM AND 370KM IN THE SOUTHWESTERN QUADRANT DUE TO THE GRADIENT EFFECT WITH THE SUBTROPICAL HIGH PRESSURES (WINDS HAS BEEN RECALIBRATED THANKS TO 1327Z AND 1636Z SCATTEROMETRY). NOAA18 IN THE NIR CHANNEL 3 AT 2143Z REVEALS A LOW LEVEL CIRCULATION CENTER EXPOSED ON THE NORTHEASTERN SECTOR OF THE MAIN CONVECTIVE ACTIVITY. THE EAST-NORTH-EASTERLY VERTICAL WINDSHEAR, CURRENTLY STRONG, SHOULD DECREASE WITHIN THE NEXT 24 HOURS. UPPER LEVEL DIVERGENCE IS GOOD, SSTS ARE OF THE ORDER OF 27/28 DEGREES CELSIUS (OCEAN HEAT POTENTIAL IS SUFFICIENT NORTH OF 13S). ENVIRONMENTAL CONDITIONS ARE FAVOURABLE TO AN INTENSIFICATION, HOWEVER RATHER SLOW. THE SYSTEM EVOLVES BETWEEN TWO COMPETING STEERING FLOWS; EQUATORWARD WELL ESTABLISHED WESTERLIES - ENHANCED BY THE CURRENT ACTIVE MJO PHASIS AND THE TWIN NORTHERN HEMISPHERE CYCLOGENESIS, AND THE WEAK TO MODERATE SUBTROPICAL RIDGE EASTERLIES. WITHIN THIS ENVIRONEMENT, THE SYSTEM SHOULD GLOBALLY DRIFT RATHER SLOWLY SOUTHWESTWARDS. THE FORECAST IS ISSUED FROM THE CONSENSUS OF THE AVAILABLE NWP AND REMAINS CLOSED OF THE EUROPEAN ECMWF SCENARIO.